I added a health check in my ASP.NET Core service (using .NET Core 3.1):
endpoints.MapHealthChecks("healthcheck", new HealthCheckOptions()
{
Predicate = _ => true,
ResponseWriter = ResponseWriter.WriteResponse
});
The health check works on http://localhost/healthcheck (there is no problem here, this works fine)
The problem is that I want to have it bound to a certain controller:
[Route("[controller]")]
[ApiController]
public class TestController : ControllerBase
Now I want the health check to be accessible under https://localhost/Test/healthcheck
The obvious answer is to set the mapping to "/Test/healthcheck" but there is a problem when there is a GET handler like this:
[HttpGet("{param}")]
public ActionResult GetTest(string param)
Because with this, accessing https://localhost/Test/healthcheck will call this GET handler with "healthcheck" as value for param and the actual health check cannot be reached.
Since in my case the accepted values for param is a predefined list, I though I could simply write an if statement to do the health check if param equals "healthcheck" but I didn't find a way to run the health check within the controller.
Is there a better way how to do this?
Or is this not even possible?
Related
I have an ASP.NET Web API I wrote and have published. Now that its out there we are looking at doing some improvements, and these improvements involve changes to certain calls which means we need to version to keep existing clients working.
I have used attribute routing so far in my app. Methods are invoked by: Controller/Action via RoutePrefix and Route attributes.
When I do need to create a V2 of my classes, I only want to recreate the classes that have actually changed, and redirect other routes back to v1 classes because they haven't changed. (Otherwise I just end up with a lot of boilerplate code, or duplicate code).
What I want to do is have the following routes work for my v1 version of classes:
Controller/Action
For V2 I want any new classes to go to V2, and any classes that haven't changed I want to return the HttpControllerDescriptor from V1 class. The route would look like v2/Controller/Action but would be redirected to Controller/Action.
I've implemented a IHttpControllerSelector and return the appropriate HttpControllerDescriptors but its not making the call into the method. I believe its because the routing information doesn't match the action. (When I put in an IHttpActionSelector and trace the exception it says "multiple actions were found that match the request).
So, I'm guess I'm wondering: Is this even possible? Is this the best way to achieve what I'm trying to do?
Here is what I implemented for versioning support in asp.net web api. Important to note I did not use attribute routing but explicit routes in WebApiConfig.cs so if you want to follow this pattern you would need to switch back to explicit routes. Also I do not prefer version information in the actual route, I use a custom (ie. "version") parameter in Accept header. I also set the version per mime type as in the below example. If version number is not set by the client or if the requested version does not exist this will fall back to default controller.
Create a class and inherit from DefaultHttpControllerSelector so you can fallback to base class behavior when you wanted to.
Override SelectController method as such:
public override HttpControllerDescriptor SelectController(HttpRequestMessage request)
{
IDictionary controllers = GetControllerMapping();
IHttpRouteData routeData = request.GetRouteData();
string controllerName = (string)routeData.Values["controller"];
HttpControllerDescriptor controllerDescriptor;
if (string.IsNullOrWhiteSpace(controllerName))
{
return base.SelectController(request);
}
if (!controllers.TryGetValue(controllerName, out controllerDescriptor))
{
return null;
}
string version = GetVersionFromAcceptHeader(request);
if (string.Equals(version, "1"))
{
return controllerDescriptor;
}
string newName = string.Concat(controllerName, "V", version);
HttpControllerDescriptor versionedControllerDescriptor;
if (controllers.TryGetValue(newName, out versionedControllerDescriptor))
{
return versionedControllerDescriptor;
}
return controllerDescriptor;
}
Register this controller selector in your webapiconfig Register method:
config.Services.Replace(typeof(IHttpControllerSelector), new YourControllerSelector(config));
I'm upgrading a custom solution where I can dynamically register and unregister Web Api controllers to use the new attribute routing mechanism. However, it seems to recent update to RTM break my solution.
My solution exposes a couple of Web Api controllers for administration purposes. These are registered using the new HttpConfigurationExtensions.MapHttpAttributeRoutes method call.
The solution also allows Web Api controllers to be hosted in third-party assemblies and registered dynamically. At this stage, calling HttpConfigurationExtensions.MapHttAttributeRoutes a second time once the third-party controller is loaded would raise an exception. Therefore, my solution uses reflection to inspect the RoutePrefix and Route attributes and register corresponding routes on the HttpConfiguration object.
Unfortunately, calling the Web Api results in the following error:
"No HTTP resource was found that matches the request URI".
Here is a simple controller that I want to use:
[RoutePrefix("api/ze")]
public sealed class ZeController : ApiController
{
[HttpGet]
[Route("one")]
public string GetOne()
{
return "One";
}
[HttpGet]
[Route("two")]
public string GetTwo()
{
return "Two";
}
[HttpPost]
[Route("one")]
public string SetOne(string value)
{
return String.Empty;
}
}
Here is the first solution I tried:
configuration.Routes.MapHttpRoute("ZeApi", "api/ze/{action}");
Here is the second solution I tried:
var type = typeof(ZeController);
var routeMembers = type.GetMethods().Where(m => m.IsPublic);
foreach (MethodInfo method in routeMembers)
{
var routeAttribute = method.GetCustomAttributes(false).OfType<RouteAttribute>().FirstOrDefault();
if (routeAttribute != null)
{
string controllerName = type.Name.Substring(0, type.Name.LastIndexOf("Controller"));
string routeTemplate = string.Join("/", "api/Ze", routeAttribute.Template);
configuration.Routes.MapHttpRoute(method.Name, routeTemplate);
}
}
I also have tried a third solution, whereby I create custom classes that implement IHttpRoute and trying to register them with the configuration to no avail.
Is it possible to use legacy-style route mapping based upon the information contained in the new routing attributes ?
Update
I have installed my controller in a Web Application in order to troubleshoot the routing selection process with the Web Api Route Debugger. Here is the result of the screenshot:
As you can see, the correct action seems to be selected, but I still get a 404 error.
Update2
After further analysis, and per Kiran Challa's comment below, it seems that the design of Web Api prevents mixing attribute routing and conventional routing, and that what I want to do is not possible using this approach.
I have created a custom attribute [RouteEx] that serves the same purpose of the Web Api [Route] attribute, and now my code works perfectly.
I guess, since this is not possible using the conventional attribute routing, none of the answers on this question could legitimately be consisered valid. So I'm not nominating an answer just yet.
You shouldn't be required to use reflection and inspect the attribute-routing based attributes yourself. Attribute routing uses existing Web API features to get list of controllers to scan through.
Question: Before the switch to attribute routing, how were you loading these assemblies having the
controllers?
If you were doing this by IAssembliesResolver service, then this solution should work even with attribute routing and you should not be needing to do anything extra.
Regarding your Update: are you calling MapHttpAttributeRoutes?
I'm having trouble setting something up that I'm pretty sure /should/ be easy, so I thought I'd throw it to the crowd. I can't seem to find what I'm looking for elsewhere on the web or on SE.
I am simplifying my project of course, but basically I have a JAX-WS annontated Jersey resource class that looks something like this:
#Path("myresource")
public class MyResource {
#Autowired
MyComplexObjectDAO daoInstance;
#Path("findObject/{id}")
#GET
public MyComplexObject findObject( #PathParam(value="id") String id ) {
return daoInstance.findObject( id );
}
#Path("saveObject")
#PUT
public MyComplexObject saveObject( MyComplexObject objectToSave ) {
MyComplexObject savedObject = daoInstance.saveObject( objectToSave );
return savedObject;
}
}
So you can see I'm autowiring a DAO object using spring, and then I use the DAO methods in the REST handlers.
The 'findObject' call seems to work fine - so far it works exactly as I expect it to.
The 'saveObject' call is not working the way I want and that's what I need some advice on.
You can see that I'm trying to directly take an instance of my complex object as a parameter to the REST method. Additionally I would like to return an instance of the complex object after it's been saved.
I put together some 'client' code for testing this out.
#Test
public void saveTest() {
WebResource wsClient = createWebServiceClient();
MyComplexObject unsavedInstance = createMyComplexObject();
MyComplexObject savedInstance =
wsClient
.path("saveObject")
.accept(MediaType.APPLICATION_XML)
.put(MyComplexObject.class, unsavedInstance);
assertNotNull(savedIntent);
}
Which is returning the following error:
com.sun.jersey.api.client.UniformInterfaceException: PUT http://localhost:8081/rest/myresource/save returned a response status of 400 Bad Request
I don't see why this isn't working and I think I've tried just about everything I can think of. Any help or direction would be very much appreciated.
Thanks so much!
I see that you call the accept() method in your test client (which means that a "Accept:" header is added to the request, indicating the server what type of representation you would like). However, you don't call the type() method to add a "Content-type:" header and inform the server that you are sending XML data. See http://jersey.java.net/nonav/documentation/latest/client-api.html#d4e644 for examples.
Side remark: your URLs are not RESTful - you should avoid verbs in your path:
So, instead of:
/api/findObject/{id}
/api/saveObject
You should use:
/api/objects/{id}
/api/objects
Last note: to create an object on calling /api/objects, you should do a POST and not a PUT to adhere to REST best practices and widely adopted patterns.
switching to the 'concrete class' solution I alluded to in my earlier comment is what fixed things up for me.
The preamble
We're implementing a MVC2 site that needs to consume an external API via https (We cannot use WCF or even old-style SOAP WebServices, I'm afraid). We're using AsyncController wherever we need to communicate with the API, and everything is running fine so far.
Some scenarios have come up where we need to make multiple API calls in series, using results from one step to perform the next.
The general pattern (simplified for demonstration purposes) so far is as follows:
public class WhateverController : AsyncController
{
public void DoStuffAsync(DoStuffModel data)
{
AsyncManager.OutstandingOperations.Increment();
var apiUri = API.getCorrectServiceUri();
var req = new WebClient();
req.DownloadStringCompleted += (sender, e) =>
{
AsyncManager.Parameters["result"] = e.Result;
AsyncManager.OutstandingOperations.Decrement();
};
req.DownloadStringAsync(apiUri);
}
public ActionResult DoStuffCompleted(string result)
{
return View(result);
}
}
We have several Actions that need to perform API calls in parallel working just fine already; we just perform multiple requests, and ensure that we increment AsyncManager.OutstandingOperations correctly.
The scenario
To perform multiple API service requests in series, we presently are calling the next step within the event handler for the first request's DownloadStringCompleted. eg,
req.DownloadStringCompleted += (sender, e) =>
{
AsyncManager.Parameters["step1"] = e.Result;
OtherActionAsync(e.Result);
AsyncManager.OutstandingOperations.Decrement();
}
where OtherActionAsync is another action defined in this same controller following the same pattern as defined above.
The question
Can calling other async actions from within the event handler cause a possible race when accessing values within AsyncManager?
I tried looking around MSDN but all of the commentary about AsyncManager.Sync() was regarding the BeginMethod/EndMethod pattern with IAsyncCallback. In that scenario, the documentation warns about potential race conditions.
We don't need to actually call another action within the controller, if that is off-putting to you. The code to build another WebClient and call .DownloadStringAsync() on that could just as easily be placed within the event handler of the first request. I have just shown it like that here to make it slightly easier to read.
Hopefully that makes sense! If not, please leave a comment and I'll attempt to clarify anything you like.
Thanks!
It turns out the answer is "No".
(for future reference incase anyone comes across this question via a search)
I have to consume a service provided by one of our partners. I was given little direction, but was told the security was to be PasswordDigest. I looked it up and immediatly saw lots of references to WSE, so off I went. It was very easy to implement and in no time I had a standard WSE user token using PasswordDigest sitting in the SOAP headers of my messages.
When we started testing today I was immediatly told (by the error message) that things weren't right. Turns out, out partner doesn't look in the SOAP header, but rather wants the security info in the http header.
I have seen lots of articles on how to add custom http headers to a proxy class, but my proxy inherits from SoapHttpClientProtocol which doesn't have a headers collection to add to. I was looking at making a raw httpWebRequest, but I have a specific method to access that has some complex parameters to deal with (and besides it feels like going backwords).
What is the best way to add custom http headers to a service proxy class that doesn't have a GetWebRequest method?
For reference:
Proxy class decleration:
[System.CodeDom.Compiler.GeneratedCodeAttribute("System.Web.Services", "2.0.50727.3053")]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Web.Services.WebServiceBindingAttribute(Name="MtomServiceSoap11", namespace="http://ws.xxxxxxx.com/")]
public partial class MtomServiceService : System.Web.Services.Protocols.SoapHttpClientProtocol {
Target method I need to call:
[System.Web.Services.Protocols.SoapDocumentMethodAttribute("", Use=System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Bare)]
[return: System.Xml.Serialization.XmlElementAttribute("uploadDocumentResponse", Namespace="http://ws.edsmtom.citizensfla.com/")]
public uploadDocumentResponse uploadDocument([System.Xml.Serialization.XmlElementAttribute(Namespace="http://ws.xxxxxxx.com/")] uploadDocumentRequest uploadDocumentRequest) {
object[] results = this.Invoke("uploadDocument", new object[] {
uploadDocumentRequest});
return ((uploadDocumentResponse)(results[0]));
}
}
The actual call to the Service is simple. The objects being pass in are not:
request.criteria = docCriteria;
request.document = document;
var result = service.uploadDocument(request);
Thanks.
It figures that 30 minutes after posting I would stumble across the answer. While the proxy class decelaration does not create a GetWebRequest method, its base class System.Web.Services.Protocols.SoapHttpClientProtocol has it and it can be overridden.
protected override System.Net.WebRequest GetWebRequest(Uri uri)
{
var request = base.GetWebRequest(uri);
request.Headers.Add("blah", "blah"); // <----
return request;
}